Merge pull request rcore-os#1 from LookCos/LookCos-patch

Update 5setup-devel-env.rst

Author: austin2035

source/chapter0/5setup-devel-env.rst

@@ -218,7 +218,7 @@ Rust 开发环境配置
 .. code-block:: bash
 
    rustup target add riscv64gc-unknown-none-elf
-   cargo install cargo-binutils --vers =0.3.3
+   cargo install cargo-binutils --version=0.3.3
    rustup component add llvm-tools-preview
    rustup component add rust-src